1. Field of the Invention
The present invention relates to an improved document feeder which automatically feeds a document onto a platen glass of a copier or an image reading apparatus and delivers the document from the platen glass after being processed.
2. Description of the Related Art
Generally speaking, this kind of document feeder is composed of; a document stock unit (a document tray) which is placed on one side of the platen glass; a document feeding means which feeds a document from the document tray onto the platen glass sheet by sheet; a document conveying means which is provided on the platen glass, which conveys the document fed from the document feeding means, sets the document at the exposure position on the platen glass, and delivers the document from the platen glass after a prescribed number of exposures are conducted; and a document delivery means which conveys an exposed document to be stacked on a delivery tray.
The above-described document feeder can be opened and closed freely with regard to the platen glass, which is installed on the upper portion of the copier. Since the document feeder is made with the above-described structure, it is possible to conduct copying of a special document, such as a stereoscopic document, a book document, and a special size document, to remove a jammed document, and to clean the platen glass. There are two types of document feeders from the viewpoint of the direction in which they open and close. One is the side opening type document feeder which opens and closes in the same direction as that of document conveyance. The other is the document feeder which opens and closes in the direction at a right angle with the document conveyance direction. These two types of document feeders are commonly used.
In the above-described document feeders, the document tray is provided on the upper portion, or on the side portion, of the copying apparatus and an exposed document is conveyed straight from the platen glass to the delivery tray which is mounted on the outside of the apparatus, or an exposed document makes a U-turn to be delivered onto the delivery tray which is provided on the upper portion of the apparatus or onto the delivery tray which is provided at a slanting upper position with regard to the above-described document tray. For that reason, the total length or the total height of the apparatus becomes so large that it has been difficult to make the apparatus compact.
Besides, the above-described large and heavy document feeder must be opened and closed with regard to the platen glass mounted on the upper portion of the apparatus. Therefore, the structure of the apparatus and the hinge to support the document feeder must be made strongly and the structure becomes complicated. Accordingly, it is hard to open and close the document feeder.